New Strong Lightweight 'Morphable' Structure
Researchers at MIT say they have created a new structure that is "10 times stiffer" than existing ultralight materials, can be easily disassembled and reassembled for maintenance or repair, and is "useful for anything you need to move or put in the air or in space." The research team says the structure is made by linking composite fiber loops and that the resulting part behaves like an elastic solid with the stiffness of much heavier traditional structures. The new structure is built from the creation of a "cubic lattice of octahedral cells," which can be engineered to be very strong in the direction of load but easily disassembled. The researchers likened that capability to the buckle on a seatbelt, which holds firm when set, but is also easy to open. And, beyond being lightweight, strong and easy to assemble, the new structure can be built to provide another feature that could be highly desirable in aircraft -- the ability to change shape.
Researchers believe that by linking multiple types of specifically engineered smaller parts made from the structure, they can make larger parts with ideal geometry that also have the ability to change shape in different ways in response to loads. "The entire arm of a robot or wing of an airplane could change shape," they said, without hinges. That would allow for greater design flexibility and possibly even more aerodynamically optimized structures that at the same time capitalize on weight savings. The weight savings begins at inception, because the technology creates parts by building up from nothing as opposed to removing material (as might be the case with metal). "Pound for pound, the new technique allows much less material to carry a given load," the researchers say. And that, they hope, could reduce manufacturing and materials costs while also producing lighter, more efficient vehicles. As for the structure's integrity, the researchers say the new structure introduces an advantage over conventional composites. Because the new material is built up from modular composition it does not fail abruptly and violently (like conventional composites) when stressed to its breaking point. According to MIT's researchers, the new structure "tends to fail only incrementally" making failure much less catastrophic and easier to repair.